Bully, a new documentary about bullying, has been rated R, which means kids under the age of 17 are not legally allowed to see it without parental supervision. But a Michigan high schooler named Katy Butler is on a mission to change that, by petitioning to get the rating lowered to PG-13. And now several celebrities are joining her in the fight!

Katy is herself a victim of bullying, so she knows how important it is for as many kids as possible to have access to this new anti-bullying documentary. She started a petition at Change.org which now has nearly 300,000 signatures. "I can’t believe the MPAA is blocking millions ofteenagers from seeing a movie that could change -- and, in some cases, save --their lives," she wrote. "According to the film’s website, over 13 million kids will bebullied this year alone. Think of how many of these kids could benefit fromseeing this film, especially if it is shown in schools?"

And now Katy has some major voices supporting her -- according to People, Ellen DeGeneres invited Katy on her show last week and said, "It'san important movie for everyone to see, especially kids." And Demi Lovato recently tweeted to her 6 million followers, "Pleasehelp repeal the R rating on 'BULLY.' EVERYONE should be able to see it. Signthe petition." Drew Brees and actor Avan Tudor Jogia also announced their support of Katy's petition.

Not only are some big Hollywood names joining in Katy's fight, she's also got the official support of over 20 members of Congress! She brought the petition, which then had about 200,000 signatures, to the Motion Picture Association of America's LA office last week, but the rating has yet to be changed.